1. Field
One embodiment of the present invention relates to an information processing apparatus and a nonvolatile semiconductor memory drive.
2. Description of the Related Art
Conventionally, there has been a semiconductor memory having a plurality of clusters each comprising a plurality of bits. As a system which manages this semiconductor memory, there is known a management system which is described, for example, in Jpn. Pat. Appln. KOKAI Publication No. 6-202962. This management system includes determination means for determining whether all bits in each cluster are normal or not, and management means for generating discrimination information which discriminates a cluster having normal bits and a cluster having defective bits, on the basis of a determination result by the determination means.
In this management system, normal bits and defective bits are discriminated and managed. It is thus possible to allocate a cluster having all normal bits to data which requires exact storage and reproduction, and to preferentially allocate a cluster including a defective bit to data which does not require exact storage and reproduction. Accordingly, since an inexpensive semiconductor memory, the quality of which is not guaranteed, can be used, the product cost can be suppressed.
In this management system, however, the creation of discrimination information is performed at the time of factory shipment of the semiconductor memory. Consequently, it is possible that even if a defect occurs in a cluster having all normal bits after shipment, the defect cannot be determined, and exact storage and reproduction of data may not be executed. It is thus required to realize a novel function for executing exact data write and exact data read-out.